1. Field of the Invention
The present invention relates to a thin film transistor and a method for manufacturing the thin film transistor, and a display device using the thin film transistor.
2. Description of the Related Art
As one type of field-effect transistor, a thin film transistor whose channel region is formed using a semiconductor film which is formed over a substrate having an insulating surface is known. Techniques in which amorphous silicon, microcrystalline silicon, or polycrystalline silicon is used for the semiconductor film which is used for the channel region of the thin film transistor have been disclosed (see Patent Documents 1 to 5). A typical application of thin film transistors is a liquid crystal display television device, in which the thin film transistors are each put to practical use as a switching transistor for each pixel in a display screen.